A power cord is an electrical cable used to connect an electrical device or appliance to a source of electrical power such as a mains electricity supply outlet or an extension cord connected to a mains outlet.
In one case, a power cord comprises a length of flexible electrical power cable, a male connector (or plug) at one end, and a female connector (socket, port or outlet) at the other end.
A power cord comprising an integrated connector at each end, one male and one female, is typically known as a cord set. Cord sets are usually detachable from the power supply and the device.
In another case, a power cord for a device has a length of flexible electrical power cable and a male connector at one end, with the other end electrically connected directly to the device. In this case, the power cable can be conjoined with the device, or at least securely fastened to the device, and is not intended be detached by a user.
An extension cord is a convenient way to provide power to an electrical device or appliance located a distance way from a suitable power outlet or source of electrical power. Like a power cord, an extension cord typically has a length of flexible electrical power cable, a male connector (or plug) at one end, and a female connector (socket, port or outlet) at the other end.
Generally, the plug and the socket are of the same type of connector, the plug connects to a mains outlet and the socket mates with a plug attached to the electrical device.
Extension cords can be used in household applications, for example to provide power to a lamp, an electronic device or a household appliance. Extension cords can also be used in construction environments and industrial applications, for example to provide power to a power tool. Extension cords can be used in indoor and outdoor situations.
The power cable in a power cord or an extension cord has a number of wires, each wire with a suitable gauge. The number of wires and the gauge of each wire is determined, at least in part, by the distance along the cable from the plug to the socket, and by the maximum electrical current to be carried by the cable.
Electrical devices such as power tools can have supplemental sockets on the body of the devices. One disadvantage is that work being done by the first device (for example a power tool) can interfere with work being done (sometimes by a different operator) by a second device connected to the supplemental socket.
Also, there is an increased risk of damage to an electrical cable supplying the second tool if it is connected to the supplemental socket on the body of the tool than if it is receiving power from a socket not located on the body of the tool.
There can also be practical limitations with locating a supplemental socket on the body of the tool, for example, size of the socket relative to the size of the tool, and heat dissipation.